Chapter 21 Review Questions

Which of the following is NOT used to treat active viral disease?

Antibiotics

People with CCR5 *delta* 32 mutation of a T-cell surface protein can be exposed to some strains of HIV-1 without becoming sick. What step of the virus life cycle is likely to be inhibited with this mutation?

Attachment

The viral _______ play(s) a role in attaching a virion to the host cell.

Capsid & Envelope

Which is true of DNA viruses?

They use the host cell's machinery to produce new copies of their genome.

Viruses......

Vary in shape

Which statement is true?

Viruses are acellular.

Oncogenic virus cores can be

either RNA or DNA

Vaccines

stimulate an immune response

Which of the following is not associated with prions?

DNA

Which statement is true of viral replication?

During attachment, the virus attaches at specific sites on the cell surface.

Which of the following statements is true about virus structure?

Glycoproteins help the virus attach to the host cell

A patient presents at the clinic with an acute viral infection. Assays that analyze the viral life cycle classify the virus into Group V with a segmented genome. Which virus is the most likely diagnosis for the patient?

Influenza A virus

Which statement is ns true of reverse transcriptase?

It transcribes RNA to make DNA

Which statement is not true of viral replication?

Newly released virions can infect adjacent cells.

A scientist discovers a new virus with a linear, RNA genome surrounded by a helical capsid. The virus is most likely a member of which family based on structure classification?

Rabies Virus

The observation that the bacteria genus Chlamydia contains species that can only survive as intracellular parasites supports which viral origin hypothesis?

Regressive

An apple grower notices that several of his apple trees with fungi growing on their trunks have developed necrotic ring spots, while other trees in the orchard tha lack the fungi appear healthy. What is the most likely conclusion the farmer can make about the virus infecting his apple tree?

The apple trees were infected by horizontal transmission

Which is true of viroids?

They are single stranded RNA particles

A bacteriophage can infect

bacteria